In a known light-emitting device, part of light from a light-emitting element is converted to light of a different wavelength by a fluorescent material, the converted light is mixed with the light from the light-emitting element, and resultant light is emitted from the light-emitting device. As an example, white light as a mixture of blue light and yellow light can be emitted by making the light-emitting element emit the blue light and making the fluorescent material convert part of the blue light to the yellow light.
Japanese Patent Application Laid-Open No. 2010-192629 (hereinafter called Patent Literature 1) discloses a structure where an adhesive layer is provided on the upper surface of a light-emitting element, and a plate-like light-transmitting member is disposed on the adhesive layer. The light-transmitting member contains a fluorescent material. Part of light emitted from the light-emitting element is converted to fluorescent light when the light passes through the light-transmitting member. Then, the fluorescent light and the light from the light-emitting element are mixed, and resultant light is emitted upward. In the structure of Patent Literature 1, a light-reflecting resin covers side surfaces of the light-emitting element and the light-transmitting member, so that light from the light-emitting element and the fluorescent light are reflected off the side surfaces. Thus, light is emitted only from the upper surface of the light-transmitting member, making it possible to obtain light of a high brightness level. Patent Literature 1 suggests formation of the light-reflecting resin at two stages so that the light-emitting element will not be covered with the adhesive layer.
In the structure of Patent Literature 1, the light-transmitting member is placed over the upper surface of the light-emitting element, and the light-reflecting member covers the light-emitting element and the light-transmitting member. In this structure, however, color unevenness is generated at an edge portion of the light-transmitting member. As an example, white light as a mixture of blue light and yellow light is emitted if light emitted from the light-emitting element is blue and fluorescent light is yellow. In this case, light becomes yellowish at the edge portion of the light-transmitting member, generating color unevenness.
The aforementioned color unevenness is generated due at least in part to the following reasons. As one reason, when blue light and yellow light are reflected off an edge surface of the light-transmitting member, the wavelength dependency of a refraction index causes the blue light and the yellow light to be reflected at different angles, generating a yellow color component and a blue color component separately. As a different reason, part of blue light caused to be reflected off the edge surface of the light-transmitting member by the light-reflecting resin is caused to be reflected again by the fluorescent material in the light-transmitting member to generate repeated reflection of the blue light between the edge surface and the fluorescent material. This makes the length of the optical path of the blue light longer before the blue light exits the light-transmitting member. Accordingly, the fluorescent material converts the wavelength of this blue light to yellow fluorescent light more easily than blue light at other parts.